I am using the Spectrum S9020 in an X-Maxx.

It runs fine for about 20 minutes, then the servo intermittently blacks out, yet the ESC and receiver are still operating fine. Sometimes it comes back to life on it's own, sometimes going in reverse kicks it back into life. A few minutes more runtime and it cuts out altogether. Disconnecting the servo lead from the power sometimes resets and gets back going, other times it is unsuccessful.

My servo gets it's power directly from a Castle BEC Pro which is wired directly to one of the battery connectors, sharing the black ground wire with the ESC (for common grounding). It is therefore being fed 4S which should allow it to handle 15 amps continuous.and 20 amp peak, more than enough and the BEC is running cool. (obviously the servo also has more than enough volts, even well after the battery has been run down to 12.8 volts)

I took temperature readings when it cut out, and on the top heat sink/metal area I am seeing 50 Celsius about 122 f

Perhaps someone knows at what temperature these servos cut out. (assuming there is a thermal protection circuit)

Does anyone have any other suggestions?

Thanks.